Created attachment 151849 [details] Contains "DoubleWave Up" and "DoubleWave Down" for testing. Open attached file. It has two slides, the first with WordArt "DoubleWave Up", the second with "DoubleWave Down". The upper object is the shape, the lower object is an image, how it looks in PowerPoint. Notice, that the path direction in the center is vertical, but it should be the same as at begin or at end. Because DrawingML text transformations are mapped to ppt-WordArt, import from pptx is effected too. But the reason of the bug is not in the newly implemented ooxml import, but in the ms-binary filter.
Regina Henschel committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/core/+/d2702aea99a93f6d3de498fda97cc1ca4f642356%5E%21 tdf#125640 correct Beziercurve control points in doublewave shapes It will be available in 6.4.0. The patch should be included in the daily builds available at https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Fix is contained in Version: 6.4.0.0.alpha0+ (x64) Build ID: c30ea50dd2b1c557dfbefc1a4c660fbf2402a604 CPU threads: 8; OS: Windows 10.0; UI render: default; VCL: win; TinderBox: Win-x86_64@42, Branch:master, Time: 2019-06-05_00:23:26 Locale: de-DE (en_US); UI-Language: en-US Calc: threaded